1. Field of the Invention
This invention relates, generally, to an propulsion device for a rider/operator. The device, which has a thrust unit coupled to a compression station with a flexible hose, through which pressurized fluid generated by the compression station is fed, is provided with three degrees of freedom (i.e., movement about three axis) between the coupling of the hose to the thrust unit and the feet of the rider/operator.
2. History of the Prior Art
Personal flight has been an eternal dream and only a fairly recent reality. However, unlike birds, human beings have a low power-to-weight ratio. It was not until Nov. 21, 1783 that the first human flight in a balloon took place. The first powered balloon flight occurred a year later. On Oct. 22, 1797, André-Jacques Garnerin was the first human to use a parachute, which was released from a balloon from an altitude of about 6,500 ft over Monceau Park in Paris.
The first heavier-than-air flight, depending on which version of history one accepts, was accomplished either by Gustave Whitehead on Aug. 14, 1901 or by Orville and Wilbur Wright on Dec. 17, 1903.
On Oct. 14, 1947—less than fifty years after the first heavier-than-air flight, U.S. Air Force Capt. Charles E. Yeager flew the Bell X-1 rocket-powered research aircraft faster than the speed of sound.
Though initially hampered by the non-existence of structural materials that were both ultra-strong and ultra-light, human-powered flight progressed from a 6.1-meter hop in 1923, to a 35.82 km English Channel crossing by Bryan Allen on Jun. 12, 1979 in the Paul MacCready-designed Gossamer Albatross and, finally, to an amazing 115.11 km flight from Iraklion on the island of Crete to Santorini, Greece in the MIT Daedalus 88 piloted by Kanellos Kanellopoulos on Apr. 23, 1988. The 1988 distance remains unsurpassed.
One might reasonably conclude that practical personal flight has only been accomplished with machines that combine powerful engines and aerodynamic airfoils. Examples of such machines include fixed wing airplanes, autogyro aircraft, and helicopters. Arguably, the closest experience to that of individual, unrestricted flight has been attained through the use of single passenger devices, consisting mainly of a rocket flight pack or similar structure that fits on or around the torso of an individual. Such devices typically require a highly flammable and explosive fuel for the development of sufficient thrust for flight. Such devices are difficult to control and invariably have very limited range.
As an alternative to employing combustible fuels to generate thrust, recreational thrust units which employ pressurized water have become popular during the past decade. U.S. Pat. No. 7,900,867 to Raymond Li, titled PERSONAL PROPULSION DEVICE, discloses a personal propulsion device including a body unit having a center of gravity, where the body unit includes a thrust assembly providing a main conduit in fluid communication with at least two thrust nozzles, with the thrust nozzles being located above the center of gravity of the body unit. The thrust nozzles are independently pivotable about a transverse axis located above the center of gravity, and may be independently controlled by a single common linkage. The present invention may further include a base unit having an engine and a pump, which provides pressurized fluid to the body unit through a delivery conduit in fluid communication with both the base unit and the thrust assembly. A more recent U.S. Pat. No. 8,336,805 to Frankie Zapata, discloses a propulsion device comprising a body arranged for receiving a passenger and engaging with a thrust unit supplied with a pressurized fluid from a compression station. The arrangement of such a device offers great freedom of movement through the air or under the surface of a fluid. The invention also relates to a propulsion system in which the compression station can be remote in the form of a motorized marine vehicle. The primary differences between the li and Zapata inventions are that the Li device is designed as a backpack, while the Zapata device is designed as a thrust pack to which the rider's feet are attached. In addition, whereas the Li device utilized a specialized, single-use compression station, the Zapata device simply couples the water outlet of a jet ski watercraft to the thrust pack with a hose. Of course, in the case of both Li and Zapata inventions, range of the propulsion devices is limited by the length of the coupling hose, and hose length is, in turn, limited by both internal friction loses and the weight of the hose and encapsulated water that must be lifted along with the rider and thrust pack.
Contemporary thrust packs have, at most, two degrees of freedom. They are typically able to rotate about the hose-coupling axis. In addition, the thrust nozzles (one under each foot) can be rotated on a single axis so that they will cause the platform, on which the rider stands, to spin. However, one of the problems associated with current thrust pack designs is that, while they work well when the end of the hose that is coupled to the thrust pack is oriented vertically, they do not work nearly as well when the rider's body is no longer perpendicular with respect to the body of water in which the ride occurs.
What is needed is a thrust pack having an additional degree of freedom so that a rider can continue to spin, even as the hose and the rider's body are inclined from the vertical.